Thesis (Ph.D.)—Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1975. / Includes bibliographical references (p. 293-303) / This electronic version was scanned from a copy of the thesis on file at the MIT Speech Communication Group. The certified thesis is available in the Institute Archives and Special Collections.

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The intrinsic laryngeal muscles are recognized as a highly specialized allotype of skeletal muscle. To date, much of the research examining the properties of this muscle group has been conducted on 2 primary muscles: the thyroarytenoid and posterior cricoarytenoid. Consequently, it is unknown whether the remaining intrinsic laryngeal muscles evidence this highly refined phenotype or if they retain a phenotype more similar to prototypical skeletal muscle. The purpose of this study was to further define the biologic properties of the interarytenoid (IA) and cricothyroid (CT) muscles of the larynx using the dystrophin deficient mdx mouse model. Previous work in this model has demonstrated sparing of select craniofacial muscles in the disease. Interestingly, a vast body of literature also supports the uniqueness of these spared muscles in a number of other areas including: fiber types, motor unit size, proprioceptive mechanisms, myosin isoform expression, remodeling behaviors, and sarcomeric structure. It follows, then, that muscle response to dystrophin deficiency serves as a sensitive marker of a muscles level of biological specialization and its similarity to or departure from classic limb muscle. Larynges and gastrocnemius muscles from 8 mdx and 8 C57BL control mice were examined histologically for typical markers of dystrophinopathy. Immunocytochemical testing examined the distribution of dystrophin and its homolog, utrophin, in control and mdx muscles. Results demonstrated that despite the absence of dystrophin, the laryngeal muscles did not show the classic markers of disease. The mdx superior cricoarytenoid muscle (SCA; mouse counterpart of human IA) demonstrated no evidence of damage, inflammation, necrosis, or regeneration. The mdx CT evidenced subtle markers of regeneration (eg, slight increase in centrally nucleated fibers) but no evidence of degeneration. The authors concluded that the SCA was spared from the effects of dystrophin deficiency, while the CT was strongly protected. The results demonstrate that the SCA and CT muscles of the larynx possess a specialized nature that separates them from prototypical limb muscle. Information from the study offers insight into the unique biology of the laryngeal muscles and holds implications for the translational study of voice and voice disorders.

Human phonation is a complex phenomenon produced by multiphysics interaction of the fluid, tissue and acoustics fields. Despite recent advancement, little is known about the effect of false vocal folds on the fluid dynamics of the glottal flow. Recent investigations have hypothesized that this pair of tissue can affect the laryngeal flow during phonation. This hypothesis was tested both computationally and experimentally in this dissertation. The computations were performed using an incompressible solver developed in fixed Cartesian grid with a second order sharp immersed-boundary formulation while the experiments were carried out in a low-speed wind tunnel with physiologic speeds and dimensions. A parametric study was performed to understand the effect of false vocal folds geometry on the glottal flow dynamics and the flow structures in the laryngeal ventricle. The investigation was focused on three geometric features: the size of the false vocal fold gap, the height between the true and false vocal folds, and the width of the laryngeal ventricle. The computational simulations were used to study the flow structures of the glottal flow and pressure distribution on the surface of the larynx. The experimental pressure data served to validate the computational results and provided extended knowledge over a broad range of Reynolds numbers. It was found that the size of the false vocal fold gap has a significant effect on glottal flow aerodynamics; whereas the height between the true and false vocal folds and the width of the laryngeal ventricle were of lesser importance. Due to lack of appreciation of the effect of real geometry of the larynx in the literature, a framework was discussed to extract the laryngeal geometry from the CT scan images. The image segmentation technique was utilized to extract the laryngeal geometries of a canine and a 45 years old female human larynx. Fully resolved three dimensional simulations of the laryngeal flow were conducted for physological Reynolds numbers in these realistic geometries to gain insight into the evolution of vortical structures in the larynx. It was shown that the glottal jet flow is highly three dimensional. The two and three dimensional computational investigations revealed the presence of the rarely reported secondary vortices in the laryngeal ventricle known as rebound vortical structures. It was found that these vortical structures are formed due to the interaction between the starting vortex ring and the false vocal folds. Therefore, the small size of the false vocal folds gap was identified as an important factor in increasing the intensity of these vortical structures. Finally, a novel high order Cartesian based moving least square finite volume solver was developed in this dissertation to model acoustic wave scattering at low Mach numbers flows. The computational aeroacoustic approach is based on incompressible viscous/acoustic splitting technique. In this solver, linearized perturbed compressible equations are solved on Cartesian grids and the boundaries are treated sharply using ghost fluid approach. The Cartesian grid framework is compatible with the incompressible solver and provides the flexibility of handling complex geometries. The acoustic solver was validated against several benchmark problems for which analytical solution is available.

Monoclonal antibodies were developed against USDA challenge strain of infectious laryngotracheitis virus (ILTV). Indirect immunofluorescence test was used to detect antibodies in supernatants of hybridomas. Hybridoma cells were developed by fusing Sp 2/0 myeloma cells with spleen cells obtained from mice immunized four times with partially purified USDA challenge strain of infectious laryngotracheitis virus. The supernatant of three hybridomas, designated as 2D1D8, 2E11G2, 2C6C7 were found positive for antibody activity against USDA challenge strain of ILTV. Hybridomas producing antibodies were cloned by the limiting dilution method. All three monoclonal antibodies reacted with USDA challenge strain of ILTV, S 88 00224 strain of ILTV, and 86 1169 strain of ILTV in an indirect immunofluorescence test. None of the monoclonal antibodies reacted with avian adenovirus 301 or parrot herpes virus in an indirect immunofluorescence test. The monoclonal antibodies were isotyped, and all three monoclonal antibodies were found to be IgM. / Graduation date: 1993

Th. Etat--Musicologie--Paris 4, 1995. / Glossaire p. 559-562. Bibliogr. p. 563-602. Index.

Loss of speech is one important factor which contributes to a decrease of life quality for patients who undergo larynx removal following for example advanced laryngeal cancer. Several devices such as the electrolarynx and the tracheo-esophageal valve prosthesis (without oscillation) have been commercialized in order to restore speech. However, such voice restoration prosthesis are still limited for certain patients. The development of a new device using a valve of variable resistance entrained by a linear electromechanical transducer was investigated as a way to produce speech for patients with total laryngectomy (ablation of vocal folds). The concept was to undertake the design of a varying air flow resistance valve, built around existing Blom-Singer valves. The oscillating valve features a spherical head making it possible to block the opening in the wall between the trachea and the esophagus in a sinusoidal periodic fashion. A physical model of the vocal tract was built and used for preliminary in-vitro verification studies. The relationship between pressure and flow rate through the valve was determined from pressure measurements. The orifice discharge coefficient of the orifice was then calculated and the parameters of a variable resistor model were identified. Radiated sound pressure produced from the change in flow rate at the valve orifice was then compared to the original voice output to assess the accuracy of the design prototype. Results showed that the forced oscillating valve prosthesis model has lower power efficiency but can produce better sound quality than the electrolarynx.

Thesis (M. Sc. Med.)--University of Sydney, 2008. / Title from title screen (viewed 29 July 2008). Submitted in fulfilment of the requirements for the degree of Master of Science in Medicine to the Discipline of Medicine, Faculty of Medicine. Degree awarded 2008; thesis submitted 2007. Includes bibliographical references. Also available in print form.

Thesis (Ph. D.)--University of Iowa, 2008. / Thesis supervisor: Eileen M. Finnegan. Includes bibliographical references (leaves 130-133).